1. Field of the Invention
This disclosure relates to optical lenses and more particularly to such lenses that effect intermediate images with simplified optical design while maintaining improved vignetting and performance.
2. Description of the Prior Art
Previous optical lens systems with intermediate images (e.g., U.S. Pat. Nos. 6,961,188, 7,009,765, and others) have been designed with too much emphasis on separating the optical system into two systems; the front group between the object and intermediate image and the rear group between the intermediate image and the final image. This method adds cost and complexity by putting constraints on the designer to correct optical aberrations such as focus, color, and thermal performance in each group separately. Also vignetting and stop position advantages are not fully realized.
Accordingly, the need remains for simplified systems with improved performance and reduced costs.